var obj = {
  name: "yz",
  age: 18
}


var info = Object.create(obj, {
  address: {
    value: "beijing",
    enumerable: true
  }
})
console.log(info);
console.log(info.__proto__);

// 方法判断
console.log(info.hasOwnProperty("address"));
console.log(info.hasOwnProperty("name"));

// in操作符
console.log("address" in info);
// for in
for(var key in info) {
  console.log(key);
}
